1. Field of the Invention
This invention relates to combustion engine starters, and more particularly to foot-operated attachments for use with already existing manual starter devices.
2. Description of the related art including information disclosed under 37 CFR .sctn..sctn.1.97-1.99
In the past, various types of foot-operated starters have been proposed and produced, for facilitating the starting of combustion engines as employed in lawn mowers and the like. The prior devices, while admittedly operative, in most cases had drawbacks and disadvantages which worked against their widespread use.
For example, U.S. Pat. No. 2,850,003 shows a pivotally-mounted foot starter for a lawn mower having a pedal 24 arranged to actuate a lever 22 which latter is attached at handle 20 to the starter cord, see FIG. 1. FIGS. 6 and 7 show a treadle bar 111 on a lever 100, 102. This device is not mechanically sound because of the possible frailties in the pivot and the long, unsupported arm of the lever 22.
In U.S. Patent No. 3,040,726 a slide 33 has a foot pad 32 and connects to the top of a vertical spiral shaft 26 to cause rotation of the latter when the pad 32 is depressed. A clutch 24 at the bottom of the shaft engages a cooperable part 23 to turn over the engine shaft. The part 35 is merely a rubber grip handle. The operating handle of the mower is not shown or involved, presumably. If the engine should "kick back" the results on the working parts could be undesirable.
A different scheme is shown in U.S. Pat. No. 3,174,471, where the handle 42 of the mower itself operates a rack 26 having teeth which mesh with a gear 13 on the shaft of the engine. This is a complicated and costly arrangement, and is not easily installed as an attachment to existing mowers. The rack, pinion and clutch must be heavy duty, to withstand any "kick-back", and will require lubrication. These are all drawbacks.
A lever-type foot-operated starter is also disclosed in U.S. Pat. No. 3,381,677, where a lever 32 is provided with a foot pedal 38, and uses a pull member 40 that passes around a pulley 44, see FIGS. 2 and 3. The absence of a sturdy foot-operated slide, however, with a good long working stroke is a disadvantage in the operation of the device.
A different approach is shown in U.S. Pat. No. 3,885,544 where an electric drill has its chuck coupled to start a combustion engine, through a suitable clutch device 22, see FIG. 2. This idea is not all that practical, due to the diversity of the powers involved, and the possibility of injury from engine kick-back.
A prior device which can be readily attached to a lawn mower is that of Glenday, U.S. Pat. No. 4,109,538. This patent shows a non-slider type of foot operator attachable to the mower handle, having a stirrup or handle 33. The device has an articulated vertical strut 36 with a pivot joint 37 by which it can be folded to foreshorten it somewhat after the engine has been started. Even so, the strut hangs pendant from the handle, and thus can be a source of interference during use of the mower. However, this construction has disadvantages due to the lack of a sturdy slide and sturdy mounting to the handle frame of the mower, and also due to the terrain and space requirements and the lack of stability.
U.S. Pat. No. 4,257,367 shows various arrangements where a foot pedal 14 is pivotally mounted to operate the pull cord of an engine for starting purposes. The use of the pivots and shafts, complicated pulley arrangements and the like are clearly drawbacks. The mechanical ratio of load to driving force makes for a dangerous situation in the event of engine kick-back, since the back force on the pedal is magnified.
U.S. Pat. No. 4,397,274 shows a number of various kinds of foot-operated starters for a mower. These are mostly characterized by pivoting assemblages, not slides, and such starters do not have the advantage of a sturdy slide that can withstand heavy foot pressures, nor the stroke advantage of a direct connection between the pull cord and the pedal.